Sample collecting method and sample collecting system

ABSTRACT

Provided is a sample collecting method for collecting a sample of soil at a predetermined depth by excavation on an extraterrestrial body or the earth. The method comprises forming a first borehole  70  that reaches a first depth from a land surface  69  by preliminary excavation of soil, the first depth being less than a predetermine sampling depth from the land surface  69 ; and forming a second borehole  73  that has a smaller opening than the first borehole and reaches a second depth from the land surface by further excavation of soil in the first borehole, the second depth being equal to or greater than the sampling depth, wherein, while forming the second borehole  73 , part of soil present at the sampling depth in the second borehole  73  is transferred to the land surface  69  as a sample for analysis.

TECHNICAL FIELD

The present invention relates to a sample collecting method and a sample collecting system suitable for collecting a sample associated with a resource present on or in an extraterrestrial body.

BACKGROUND ART

Advances in space exploration technology have revealed that various useful resources exist in extraterrestrial bodies. When mining resources from underground on an extraterrestrial body (such as the Moon or Mars), equipment that can be used is very restricted compared to that usable on the earth. Thus, a number of technologies have been developed to create equipment that can be used for mining of resources in an extraterrestrial body.

One example of known such technology is a resource mining method in which gas is blown into sand on an extraterrestrial body (such as the Moon) to fluidize the sand, thereby facilitating mining of a resource berried in the sand. (See Patent Document 1)

Another example of known such technology is an excavation apparatus which is usable for excavation on the ground of an extraterrestrial body, including a propulsion mechanism for providing propulsion based on peristaltic motion, and an earth auger having a tip part for excavation and a rear part for transferring soil and sand, where the tip part and the rear parts have different respective diameters. (See Patent Document 2)

PRIOR ART DOCUMENT(S) Patent Document(s)

Patent Document 1: JP2019-148155A

Patent Document 2: JP2011-169056A

SUMMARY OF THE INVENTION Task to be Accomplished by the Invention

In order to efficiently extract a necessary resource from underground on an extraterrestrial body (e.g., the Moon or Mars), a preliminary investigation needs to be carried out to identify a position (including a depth from the land surface) where a target resource exists, and estimate its extent of abundance. Such an investigation generally involves: collecting a piece of soil (such as a mixture of minerals, water, sand, and other components) as a sample which is present at a predetermined depth and expected to contain resources; and analyzing components in the collected sample to determine what percentage of a target resource is contained in the sample soil.

However, in the case of the resource mining method of Patent Document 1, the method essentially requires blowing gas into sand prior to mining of a resource to fluidize the sand, which makes it difficult to accurately determine the depth (from the land surface) of a position where a collected sample was initially present. Moreover, in the method of Patent Document 1, the fluidization operation before collection of a sample inevitably causes damage to soil and sand of a region around a sampling point where a sample is collected. (That is, the fluidization operation makes it difficult to preserve the condition of a region surrounding the sampling point.) Accordingly, when re-sampling is performed at a point near the prior sampling point, a sampling result becomes less reliable.

In the case of the excavation apparatus of Patent Document 2, when the depth of a sampling point is deep from the land surface, it is necessary to use a very long screw that is long enough to reach the sampling point. As a result, the size of the apparatus equipped with a screw become large, which makes it difficult to handle the apparatus (such as transportation of the apparatus from the earth to an extraterrestrial body). In addition, as the excavation apparatus of Patent Document 2 uses a complex mechanism such as a propulsion mechanism, the apparatus needs to perform electronic control of such a complex mechanism, which control is susceptible to adverse effects from cosmic radiation.

The present invention has been made in view of these problems of the prior art, and a primary object of the present invention is to provide a sample collecting method and a sample collecting system which are simply configured and enable sample collection at a predetermined depth without increasing the size of equipment for excavating soil for sample collection.

Means to Accomplish the Task

An aspect of the present invention, which has been made to accomplish the above-described task, provides a sample collecting method comprising: forming a first borehole that reaches a first depth from a land surface by preliminary excavation of soil, the first depth being less than a predetermined sampling depth from the land surface; forming a second borehole that has a smaller opening than the first borehole and reaches a second depth from the land surface by further excavation of soil in the first borehole, the second depth being equal to or greater than the sampling depth; and while forming the second borehole, transferring part of soil present at the sampling depth in the second borehole to the land surface as a sample for analysis.

In this configuration, the sample collecting method comprises: forming a first borehole that reaches a first depth which is less than a predetermined sampling depth; forming a second borehole that reaches a second depth which is equal to or greater than the sampling depth. Thus, the method is simply configured and enables sample collection at a predetermined depth without increasing the size of equipment for excavating soil for sample collection.

In the above aspect, the method may be configured such that the step of forming the first borehole is performed by a preliminary excavation apparatus with a scoop or a blade.

In this configuration, using the preliminary excavation apparatus with a scoop or a blade makes it easy to form the first borehole that reaches a first depth, which is less than a predetermined sampling depth.

In the above aspect, the method may be configured such that the step of forming the second borehole is performed by a main excavation apparatus with a screw.

In this configuration, using main excavation apparatus with a screw makes it possible to precisely perform sample collection at a predetermined sampling depth. Furthermore, use of the screw as equipment for excavating soil for sample collection causes less damage to the condition of soil (surrounding environment) of a region around the sampling position (that is, a peripheral region around the borehole formed by the screw).

In the above aspect, the method may be configured such that the step of forming the first borehole comprises forming a bottom surface and a sloped side surface connecting the bottom surface with the land surface, and wherein the step of forming the second borehole comprises moving the main excavation apparatus through the sloped side surface to the bottom surface.

In this configuration, use of the sloped side surface of the first borehole makes it easy to move the main excavation apparatus for excavating soil for sample collection, from the land surface to the bottom surface the first borehole (where the second borehole is formed).

In the above aspect, the method may be configured such that the step of forming the first borehole is performed by blasting soil on the land surface.

In this configuration, which has been made up considering the fact that the first borehole does not need to have a precise length of the first depth (as the second depth of the second borehole can be adjusted so as to reach a precise sampling point even when there is some error in the first depth of the first borehole), use of blasting soil on the land surface makes it easy to form the first borehole reaching the first depth, which is less than the sampling depth.

In the above aspect, the method may be configured to further comprise a sample supply step for supplying at least a portion of the sample for analysis that has been transferred to the land surface, to a sample analyzing apparatus installed on the land surface.

This configuration makes it possible to analyze analyte components of a sample for analysis, while minimizing deterioration of the soil sample due to long-term transportation or other reason.

In the above aspect, the method may be configured to further comprises a separation step for separating one or more analyte components from the sample for analysis by processing the sample for analysis that has been transferred to the land surface, wherein the sample supply step comprises supplying the one or more analyte components to the sample analyzing apparatus as part of the sample for analysis.

This configuration makes it easy to analyze desired analyte components by using the sample analyzing apparatus.

In the above aspect, the method may be configured such that the separation step comprises separating water as an analyte component from the sample for analysis by heating the sample for analysis.

This configuration makes it easy to analyze the gas containing water, which is separated from the sample for analysis, by using the sample analyzing apparatus.

Another aspect of the present invention provides a sample collecting system comprising: a preliminary excavation apparatus for forming a first borehole that reaches a first depth from a land surface by preliminary excavation of soil, the first depth being less than a predetermined sampling depth from the land surface; and a main excavation apparatus for forming a second borehole that has a smaller opening than the first borehole and reaches a second depth from the land surface by further excavation of soil in the first borehole, the second depth being equal to or greater than the sampling depth, wherein the main excavation apparatus comprises a screw for excavation, and wherein, by rotating the screw, part of soil present at the sampling depth in the second borehole is transferred to the land surface as a sample for analysis.

In the thus-configured sample collecting system, the preliminary excavation apparatus is used to form a first borehole that reaches a first depth which is less than a predetermined sampling depth, and then the main excavation apparatus is used to form a second borehole that reaches a second depth which is equal to or greater than the sampling depth. Thus, the system is simply configured and enables sample collection at a predetermined depth without increasing the size of equipment for excavating soil for sample collection.

In the above aspect, the system may be configured such that the preliminary excavation apparatus is provided with a scoop or a blade.

In this configuration, the system uses a preliminary excavation apparatus with a scoop or a blade, which makes it easy to form the first borehole that reaches a first depth, which is less than a predetermined sampling depth.

In the above aspect, the system may further comprise a sample analyzing apparatus installed on the land surface and configured to analyze one or more analyte components included in the sample for analysis that has been transferred to the land surface.

This configuration makes it possible to analyze analyte components of a sample for analysis, while minimizing deterioration of the soil sample (analyte components) due to long-term transportation or other reason.

In the above aspect, the system may be configured such that the main excavation apparatus is movable between a standby position in which the main excavation apparatus lies horizontally along the land surface and an operating position in which the main excavation apparatus stands upright relative to the land surface, and wherein the sample analyzing apparatus is moved between the standby position and the operating position together with the main excavation apparatus.

This configuration makes it possible to supply a sample for analysis to the sample analyzing apparatus immediately after the sample for analysis is transferred from underground to the land surface, thereby preventing deterioration of the soil sample more effectively.

In the above aspect, the system may further comprise a sample processing apparatus configured to perform a heat treatment process for separating gas containing water, the water being an analyte component, from the sample for analysis.

This configuration makes it easy to analyze the gas containing water (an analyte component), which is separated from the sample for analysis, by using the sample analyzing apparatus.

In the above aspect, the system may be configured such that the main excavation apparatus comprises a hollow rod configured to accommodate the screw, wherein the hollow rod defines an opening for discharging the sample for analysis that the screw has transferred to the land surface, and wherein the sample analyzing apparatus is installed at a location where the sample for analysis discharged from the opening falls by gravity.

This configuration makes it easy to easily supply a sample for analysis to the sample analyzing apparatus after the sample for analysis is transferred from underground to the land surface by the main excavation apparatus.

In the above aspect, the system may be configured such that the sample processing apparatus comprises: a core formed with a recess for accommodating the sample for analysis for the heat treatment process; and an outer cylinder arranged to surround the core, wherein the core is rotatably provided within the outer cylinder, wherein the outer cylinder defines a sample inlet that is a through hole into which the sample for analysis is provided, and wherein the sample inlet is formed such that the recess is brought into communication with an outside environment through the sample inlet only when the core is at a predetermined rotational position.

This configuration makes it easy to provide a sample to be analyzed, which has been transferred from underground to the land surface, into the recess formed in the sample processing apparatus.

In the above aspect, the system may further comprise a vehicle equipped with the preliminary excavation apparatus, the main excavation apparatus, and the sample analyzing apparatus.

In this configuration, even when being on an extraterrestrial body, the sample collecting system can be easily moved to a place where a sample is to be collected.

Effect of the Invention

The above-described methods and systems can be simply configured and enable sample collection at a predetermined depth without increasing the size of equipment for excavating soil for sample collection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an overall configuration of a sample collecting system according to one embodiment of the present invention;

FIG. 2 is a plan view showing an internal structure of a system main body;

FIG. 3 is a side view showing the internal structure of the system main body;

FIG. 4 is a side view showing the system main body with a main excavation apparatus in an operating state;

FIG. 5 is a partially transparent perspective view of the sample processing apparatus;

FIG. 6 is a cross-sectional view cutting along line Va-Va, showing an internal structure of the sample processing apparatus;

FIG. 7 is a cross-sectional view cutting along line Vb-Vb, showing the internal structure of the sample processing apparatus;

FIG. 8 is an explanatory diagram showing a series of operations related to sample collection performed by the sample collecting system;

FIG. 9 is an explanatory diagram showing how a sample is introduced into the sample processing apparatus in the operation (e) in FIG. 8 ;

FIG. 10 is an explanatory diagram showing an example of how the sample processing apparatus operates in the operation (e) in FIG. 8 ;

FIG. 11 is a block diagram showing a control system of the sample collecting system; and

FIG. 12 is a sequence diagram showing a procedure of operations of a sample collection process performed by the sample collecting system.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Embodiments of a sample collecting method and a sample collecting system of the present invention are described in the following with reference to the appended drawings. Various direction-indicating terms are used herein as a convenient way to discuss the embodiments, and refer to the corresponding directions (such as up/down, front/rear, and right/left) illustrated using arrows in the drawings.

FIG. 1 is a diagram showing an overall configuration of a sample collecting system 1 according to one embodiment of the present invention. The sample collecting system 1 is used, for example, on an extraterrestrial body to collect samples of underground resources. The present embodiment shows an example in which the sample collecting system 1 and a sample collecting method performed by the system are used for collection of samples related to resources (in this case, water) present in a surface layer of the Moon.

The sample collecting system 1 includes a vehicle 2 capable of traveling on the surface of the Moon. The vehicle 2 includes a travel device 10 and a chassis 11 supported by the travel device 10. The chassis 11 is provided with a preliminary excavation apparatus 12 for performing preliminary excavation of soil where a target resource is expected to be present. The chassis 11 is also provided with a main excavation apparatus 13 for performing main excavation of soil; that is, excavation of soil from a site where the preliminary excavation has been performed (i.e., where a borehole is formed to a certain depth) to a point of a predetermined sampling depth, where the main excavation is further performed in a more precise manner than the preliminary excavation; that is, so as to reach a more precise point. The main excavation apparatus 13 is installed in a system main body 14, which is a vehicle body in this case. The system main body 14 includes a baseplate 20 attached to the left side of the chassis 11. The main excavation apparatus 13 is mounted on the baseplate 20. The baseplate 20 is configured to be vertically movable relative to the chassis 11. In some cases, the sample collecting system 1 may be configured without the preliminary excavation apparatus 12.

In the present embodiment, the vehicle 2 is an unmanned rover which can operate autonomously or remotely. The travel device 10 includes a plurality of crawlers 15 arranged on the front, back, left and right sides, respectively, where each crawler can be driven by a motor (not shown). However, the vehicle 2 is not limited to the configuration as illustrated, and may be any mobile body at least capable of moving on the ground or flying at a low altitude.

The preliminary excavation apparatus 12 includes a shovel having a scoop 16, an arm 17 and a boom 18 pivotally supporting the scoop 16, and a support device 19 pivotally supporting the boom 18. The support device 19 includes a drive device (not shown) for driving the scoop 16, the arm 17 and the boom 18. The support device 19 is provided so as to be movable relative to the chassis 11 in the front-rear direction. In some cases, the preliminary excavation apparatus 12 may use a blade instead of the scoop 16 as an excavation instrument. The preliminary excavation apparatus 12 is not limited to a shovel, and may be any apparatus at least capable of excavating soil.

FIGS. 2 and 3 are a plan view and a side view showing an internal structure of the system main body 14. In FIGS. 2 and 3 , the main excavation apparatus 13 is in a standby state (i.e., a standby position). FIG. 4 is a side view showing the system main body 14 with the main excavation apparatus 13 which is in an operating state (i.e., an operating position).

As shown in FIG. 2 , the system main body 14 includes the main excavation apparatus 13, a sample processing apparatus 22, a sample analyzing apparatus 23, an apparatus movement mechanism 24, a power supply device 26, and a main control device 27.

The main excavation apparatus 13 includes an excavation drill. The excavation drill includes a screw 31 extending in the front-rear direction; a hollow rod 32 extending in the front-rear direction and configured to accommodate the screw 31; and a main-excavation-related motor 33 coupled to the rear end of the screw 31 and configured to drive the rotation of the screw 31. A blade 31A of the screw 31 has substantially the same outer (maximum) diameter over the whole length in the axial direction (the front-rear direction).

The main excavation apparatus 13 may be any apparatus capable of excavating soil from the bottom surface of the borehole formed by preliminary excavation conducted by the preliminary excavation apparatus 12, to a predetermined sampling depth, and then collecting part of soil at the sampling depth in a small amount, i.e., an amount required for analysis. (Hereafter, such a small amount of collected soil is referred to as “sample for analysis”.) Thus, an excavation drill used for the main excavation apparatus 13 is a relatively small one, which is different from excavation drills commonly used for construction work or other applications. The screw 31 used by the main excavation apparatus 13 and to be inserted into the ground, has a relatively small outer diameter and an axial length. (For example, such a screw 31 may have an outer diameter of about 10-20 mm and a length of about 500-1000 mm.)

The sample processing apparatus 22 separates gas containing an analyte component (e.g., water in the present embodiment) from a sample for analysis collected by the main excavation apparatus 13. In the system main body 14, the sample processing apparatus 22 is provided so as to be moved together with (or integrally with) the main excavation apparatus 13 when the main excavation apparatus 13 moves (e.g., when changing between the operating position (operating state) and the standby position and the operating position, or when performing excavation of soil (or retreat)). In the present embodiment, the sample processing apparatus 22 is secured to the rear part of the hollow rod 32. In addition, the sample processing apparatus 22 is provided with a sample-processing-related motor 35 for rotationally driving a core 51 (see FIG. 5 ), which will be described later.

The sample analyzing apparatus 23 comprises a gas analyzer. The gas analyzer is configured to measure the optical absorption spectrum of gas containing analyte components, the gas being supplied from the sample processing apparatus 22, by near-infrared semiconductor laser spectroscopy; and calculate the concentration of each component contained in the gas from the peak area and height of the spectrum curve. When the analyte component is water, the sample analyzing apparatus 23 has a higher spectral resolution than an infrared moisture analyzer, and can perform measurements while being almost unaffected by interference gases or a reduction in the amount of transmitted light due to dirt on the optical window. The sample analyzing apparatus 23 is provided in the system main body 14 so as to be moved together with (or integrally with) the main excavation apparatus 13 when the main excavation apparatus 13 moves in a similar manner to the sample processing apparatus 22. The sample analyzing apparatus 23 can be directly or indirectly secured in place on the main excavation apparatus 13.

The apparatus movement mechanism 24 includes a rotation shaft 41, bearings 42 and 43 for supporting both ends (the left and right ends) of the rotation shaft 41, and a motor 44 for driving the rotation shaft 41. Coupled to the left end of the rotation shaft 41 is a holder 46 for holding the hollow rod 32 of the main excavation apparatus 13 so that the hollow rod 32 can be moved back and forth (up and down in FIG. 4 ). Coupled to the right end of the rotation shaft 41 is one end of a support frame 47 for supporting the sample analyzing apparatus 23. The support frame 47 supports the sample analyzing apparatus 23 so that the sample analyzing apparatus 23 is movable in the front-rear direction (downward in FIG. 4 ). In some cases, the holder 46 may include a drive mechanism for drivingly moving the hollow rod 32.

In the apparatus movement mechanism 24, when the rotation shaft 41 rotates, the holder 46 (i.e., the hollow rod 32) and the support frame 47 (i.e., the sample analyzing apparatus 23), which are coupled to the left and right ends of the rotation shaft 41, respectively, also rotate. As a result, the main excavation apparatus 13 moves from the standby position shown in FIG. 3 to the operating position shown in FIG. 4 . In the standby position, the main excavation apparatus 13 lies horizontally (that is, the axial along the screw 31 is substantially parallel with the land surface), while, in the operating position, the main excavation apparatus 13 stands upright relative to the land surface. In the present embodiment, when the main excavation apparatus 13 is in the operating position, the axial direction of the screw 31 is substantially the vertical direction (In this case, the direction perpendicular to the land surface of the Moon). However, the apparatus in the operating position does not limitedly take this upright form, and the axial direction of the screw 31 (that is, the excavation direction of the main excavation apparatus 13) may be directed obliquely relative to the land surface.

Thereafter, when the motor 33 is started, the main excavation apparatus 13 moves downward, excavating soil as shown in FIG. 4 . The soil excavated by the screw 31 is transferred upward (in the direction opposite to the excavation advancing direction) through the hollow rod 32. In this situation, the hollow rod 32 moves downward together with the screw 31 while being supported by the holder 46. Also, the sample processing apparatus 22 secured to the main excavation apparatus 13 moves together with the main excavation apparatus 13. Similarly, the sample analyzing apparatus 23 provided to the main excavation apparatus 13 moves together with the main excavation apparatus 13 while being supported by the support frame 47. The sample analyzing apparatus 23 slides along guide rails (not shown) of the support frame 47.

The power supply device 26 is mounted on the baseplate 20 and controlled by the main control device 27 to supply power for use in the sample collecting system 1.

The main control device 27 is mounted on the baseplate 20 and is configured to control each device in the sample collecting system 1. The main control device 27 includes: one or more processors for performing various types of data processing and control of peripheral devices by executing predetermined control programs, one or more RAMs (Random Access Memory) for providing a work area of each processor, one or more ROMs (Read Only Memory) for storing data and control programs executed by the processors, and a network interface for controlling wireless communications and other related operations. However, the configuration of the main control device 27 is not limited to the present embodiment. The main control device 27 preferably adopts a configuration that is less susceptible to cosmic radiation.

FIG. 5 is a partially transparent perspective view of the sample processing apparatus 22. FIGS. 6 and 7 are cross-sectional views cutting along line Va-Va and line Vb-Vb, respectively, showing an internal structure of the sample processing apparatus 22.

The sample processing apparatus 22 includes a substantially cylindrical core 51 and a substantially cylindrical outer cylinder 52 surrounding the core 51.

As shown in FIGS. 6 and 7 , the core 51 defines a recess 55 for accommodating part of the soil extracted by the main excavation apparatus 13 as a sample to be analyzed. The recess 55 opens on the outer surface of the core 51 facing (sliding contacting) the inner surface of the outer cylinder 52. A heater 57 for heating a sample to be analyzed is provided in the recess 55. The heater 57 can heat a sample to be analyzed in the recess 55 to a predetermined temperature (for example, about 100 to 200° C.). In the present embodiment, heating a sample for analysis by the heater 57 results in vaporizing moisture (water) contained in the sample in the recess 55.

As shown in FIG. 5 , a plurality of measurement holes 58 open on the right surface 51A of the core 51, so that a thermometer (not shown) such as a thermocouple can be inserted through an opening to measure the temperature of the recess 55 (that is, the temperature of the sample to be analyzed) so that a thermometer (not shown) such as a thermocouple can be inserted into a measurement hole 58 to measure the temperature of the recess 55 (that is, the temperature of a sample to be analyzed). A shaft 35A of the motor 35 (see FIG. 2 ) is coupled to the right surface 51A of the core 51. As a result, the core 51 is rotatable in the outer cylinder 52 about the axis extending in the left-right direction. Furthermore, a vent hole 59 opens on the right surface 51A of the core 51 for discharging the gas analyzed by the sample analyzing apparatus 23 to the outside. The vent hole 59 has an axial portion 59A extending axially from the right surface 51A of the core 51 and a radial portion 59B extending radially to the outer peripheral surface (see FIG. 6 ).

The core 51 may be provided with a weight sensor for measuring the weight of a sample to be analyzed in the recess 55.

The outer cylinder 52 defines a sample inlet 61 into which a sample for analysis collected by the main excavation apparatus 13 can be introduced. The sample inlet 61 is a through hole extending radially in the upper portion of the outer cylinder 52 from the outer surface to the inner surface. The sample inlet 61 is in communication with the recess 55 of the core 51 when the core 51 is at a predetermined rotational position, as shown in FIG. 6 . In some cases, the sample inlet 61 may have a tapered shape such that the inner diameter gradually increases in the direction from the inner surface to the outer surface of the outer cylinder 52 (from the “down” side to the “up” side in FIG. 5 ).

The outer cylinder 52 defines a gas delivery port 63 for delivering gas containing one or more analyte components to the sample analyzing apparatus 23, the analyte components being separated from a sample to be analyzed by the heat treatment process in the recess 55. The gas delivery port 63 is a through hole extending radially on the upper side of the outer cylinder 52 from the outer surface to the inner surface. A sintered metal filter 64 (see FIG. 6 ) is disposed in the gas delivery port 63. The gas delivery port 63 is in communication with the recess 55 when the core 51 is at a predetermined rotational position for delivery. The gas delivery port 63 is also in communication with the vent hole 59 when the core 51 is at a predetermined rotational position for vent, which, however, is different from the predetermined rotational position for delivery at which the gas delivery port 63 is in communication with the recess 55.

The outer cylinder 52 defines a sample discharge port 67 for discharging an analyzed sample from the recess 55 to the outside. The sample discharge port 67 is a through hole extending radially in the lower portion of the outer cylinder 52 from the outer surface to the inner surface. The sample discharge port 67 is in communication with the recess 55 of the core 51 when the core 51 is at a predetermined rotational position for sample discharge. Also, the sample discharge port 67 is in communication with the vent hole 59 when the core 51 is at a predetermined rotational position for sample vent. In some cases, the sample discharge port 67 may have a tapered shape such that the inner diameter gradually increases in the direction from the inner surface to the outer surface of the outer cylinder 52 (from the “up” side to the “down” side in FIG. 5 ).

The sample processing apparatus 22 does not necessarily be used in combination with other apparatuses in the sample collecting system 1 shown in the present embodiment, and can be used in other systems different from the sample collecting system 1.

FIG. 8 is an explanatory diagram showing a series of operations related to sample collection performed by the sample collecting system. FIG. 9 is an explanatory diagram showing how a sample is introduced into the sample processing apparatus 22 in the operation (e) in FIG. 8 . FIG. 10 is an explanatory diagram showing an example of how the sample processing apparatus 22 operates in the operation (e) in FIG. 8 .

As shown in FIG. 8 , in the process for sample collection performed by the sample collecting system 1, first, the vehicle 2 moves to a sampling location where sample collection is to be performed (see operation (a)).

Next, the sample collecting system 1 starts provisional excavation using the preliminary excavation apparatus 12 (see operation (b)). In this operation, preliminary excavation may be done by blasting soil on the land surface 69 using known techniques, instead of using the preliminary excavation apparatus 12. Alternatively, partial preliminary excavation may be done by blasting soil on the land surface 69 before starting preliminary excavation by the preliminary excavation apparatus 12.

The operation of preliminary excavation forms a preliminary borehole 70 (first borehole) with a size that allows the vehicle 2 to enter the borehole (see operation (c)). The preliminary borehole 70 is defined by a bottom surface 70A substantially parallel to the land surface 69, and a sloped side surface 70B connecting the bottom surface 70A with the land surface 69. As such, the preliminary borehole 70 allows the vehicle 2 with the main excavation apparatus 13 to move down the sloped side surface 70B and then reach the bottom surface 70A. Excavated soil is piled up as surplus soil (soil mass) 71 outside the preliminary borehole 70. The preliminary borehole 70 reaches a first depth (2L) which is less than a sampling depth (3L), the sampling depth being a predetermined depth from the land surface 69. The first depth is determined based on the depth that can be excavated by the main excavation apparatus 13 (that is, the first depth is determined such that the main excavation apparatus 13 can form a borehole from a bottom surface 70A of the preliminary borehole 70 to the sampling depth).

Next, the sample collecting system 1 starts main excavation using the main excavation apparatus 13 from within the preliminary borehole 70 (see operation (d)). In this operation, the system main body 14 (that is, the baseplate 20) descends from its upper position (initial position) shown in FIG. 1 to its lower position on the bottom surface 70 a of the preliminary borehole 70. Then, driven by the apparatus movement mechanism 24, the main excavation apparatus 13 moves from its standby position, in which the apparatus lies horizontally, to its operating position, in which the apparatus stands substantially upright. After the completion of the position-change movement, the main excavation apparatus 13 excavates soil from the bottom surface 70A of the preliminary borehole 70 to a point of the predetermined sampling depth.

The main excavation apparatus 13 performs the operation of main excavation to form a main borehole 73 (second borehole) in the bottom surface 70A of the preliminary borehole 70 (see operation (e)). The main borehole 73 has a smaller opening than the preliminary borehole 70 and a second depth (1L) that reaches the sampling depth. The main borehole 73 may have any depth as the second depth as long as a sum of the second depth and the first depth is equal to or greater than the sampling depth. If necessary, the main borehole 73 may extend deeper beyond a point of the sampling depth.

While the main excavation apparatus 13 performs the operation of main excavation to form the main borehole 73, excavated soil in the main borehole 73 is transferred to the land surface. As shown in FIG. 9 , the hollow rod 32 of the main excavation apparatus 13 has an opening 32A for sampling, which is located above the sample processing apparatus 22 when the main excavation apparatus is in the upright operating state. Soil transferred upward in the hollow rod 32 by the blade 31A of the screw 31 is discharged continuously from the opening 32A and falls onto the sample processing apparatus 22 by gravity. Then, part of the soil introduced into the sample processing apparatus 22 is used as a sample for analysis.

In addition, while the main excavation apparatus 13 performs the operation of main excavation, the sample processing apparatus 22 processes a sample for analysis, and then the sample analyzing apparatus 23 analyzes the processed sample, as shown in FIG. 10 .

The sample processing apparatus 22 is provided with a shutter 81 for opening and closing the sample inlet 61. When the main excavation is started, the shutter 81 is in its closed position for closing the sample inlet 61 (see operation (A) in FIG. 10 ). The shutter in the closed position prevents introduction of soil into the sample inlet 61 before the excavation reaches a point for sample collection; that is, blocks soil that was present at positions shallower than the sampling depth. When the shutter in the closed position, the core 51 is at rotational position where its recess 55 opens downward (i.e., the recess 55 is in communication with the sample discharge port 67).

Then, when excavation has been advanced by the main excavation apparatus 13 to reach a point where a sample for analysis is transferred to be discharged from the opening 32A (see FIG. 9 ), the shutter 81 moves to the open position to thereby open the sample inlet 61 (see operation (B)). As a result, part of the soil dropped from the opening 32A of the hollow rod 32 is introduced into the sample inlet 61 as a sample to be analyzed. Before (or at the same moment) the shutter 81 is opened, the core 51 rotates by a predetermined amount (180° in this case) to reach the rotational position where the recess 55 opens upward (i.e., the recess 55 is in communication with the sample inlet 61). When the sample to be analyzed introduced from the sample inlet 61 is completely accommodated in the recess 55, the shutter 81 moves back to the closed position.

Next, in the sample processing apparatus 22, the core 51 rotates by a predetermined amount (60° in this case) to reach the rotational position where the recess 55 is in communication with the gas delivery port 63 (see operation (C)). At the same moment, the heater 57 is activated in the sample processing apparatus 22 to heat the sample to be analyzed in the recess 55 for a predetermined period of time. As a result, moisture (water) contained in the sample to be analyzed is vaporized, and the gas containing the vaporized moisture is delivered to the sample analyzing apparatus 23 (see FIG. 4 ) through the gas delivery port 63. Upon receiving the gas containing water from the sample processing apparatus 22, the sample analyzing apparatus 23 measures the concentration of each component contained in the gas. A result of the analysis indicates the percentage of water, which is an analyte component, in a piece of soil at a certain sampling depth. The gas delivery port 63 of the outer cylinder 52 is communicably connected to an analyte gas inlet of the sample analyzing apparatus 23 via tubing (not shown).

Thereafter, in the sample processing apparatus 22, the core 51 rotates by a predetermined amount (120° in this case) to reach the rotational position where the recess 55 is in communication with the sample discharge port 67 (see operation (D)). As a result, the sample to be analyzed in the recess 55 is discharged to the outside through the sample discharge port 67 (that is, dropped from the sample discharge port 67 by gravity). When the sample is discharged to the outside, the radial portion 59B of the vent hole 59 is at such a position that the vent hole 59 is in communication with the gas delivery port 63. As a result, the analyzed gas from the sample analyzing apparatus 23 is returned to the vent hole 59 of the sample processing apparatus 22 and discharged to the outside from the opening of the axial portion 59A.

FIG. 11 is a block diagram showing a control system of the sample collecting system 1.

The sample collecting system 1 includes: a vehicle control device 91 for controlling the travel device 10; an excavation control device 92 for controlling the preliminary excavation apparatus 12 and the main excavation apparatus 13; a sample processing control device 93 for controlling the sample processing apparatus 22; and a sample analyzing control device 94 for controlling the sample analyzing apparatus 23. Each of these control devices 91 to 94 performs control operations responsive to commands delivered from the main control device 27.

The vehicle control device 91 is attached to the travel device 10 and configured to control the traveling of the vehicle 2, which includes steering of the vehicle 2, to thereby move the sample collecting system 1 to a desired sampling location. The vehicle control device 91 features the ability to measure the position (coordinates) of the vehicle 2 on the Moon, using a known technology (e.g., Very-Long-Baseline Interferometry (VLBI)).

The excavation control device 92 selectively controls the preliminary excavation apparatus 12 and the main excavation apparatus 13 (that is, switches the operating states of the preliminary excavation apparatus 12 and the main excavation apparatus 13 as appropriate) to thereby perform preliminary excavation and main excavation in order. The excavation control device 92 includes a known device capable of measuring the insertion depth of the main excavation apparatus 13 (screw 31) inserted into the ground.

The sample processing control device 93 controls the motor 35 for rotationally driving the core 51, the heater 57 for heating a sample to be analyzed in the sample processing apparatus 22, and executes other controls. The sample processing control device 93 performs the controls, so that, upon receiving a sample to be analyzed, the sample processing apparatus 22 can execute processing of the sample to be analyzed (e.g., a process of separating gas containing moisture from the sample to be analyzed, in this case). The sample processing control device 93 can move (rotate) the core 51 with controlling the amount of rotation so as to reach a certain rotational position at which any of the operations (A) to (D) in FIG. 10 is performed. The sample processing control device 93 includes a sensor for detecting the rotational position of the core 51, a timer for detecting the time for the opening or closing the shutter 81, and other features.

The sample analyzing control device 94 controls the sample analyzing apparatus 23 to execute the analysis of a sample to be analyzed (analyte component). In addition, the sample analyzing control device 94 transmits a result of the analysis to the main control device 27 where the result is stored.

The power supply device 26 is provided with a battery 96. The power supply device 26 is controlled by the main control device 27 to supply power from the battery 96 to any of the devices and apparatuses in need of electric power in the sample collecting system 1. The power supply device 26 may include a known power generator (such as a solar power generator) for charging battery 96 as necessary.

It should be noted that the main control device 27 and the respective control devices 91 to 94 are not necessarily separate devices, and two or more of these control units may be incorporated in a single control device.

FIG. 12 is a sequence diagram showing a procedure of operations of a sample collection process performed by the sample collecting system.

In the sample collection process, first, the sample collecting system 1 acquires sampling position information as information on a place where samples should be collected (ST101). The sampling position information is previously stored in a memory of the main control device 27, or acquired by the system through communication with an external device (e.g., an information processing device on the earth). The sampling position information includes, for example, position coordinates determined on the surface of the extraterrestrial body (the Moon in this case) and depth values from the land surface.

Next, the sample collecting system 1 determines a destination (sampling place) based on the sampling position information acquired in step ST101, and moves the vehicle 2 to the destination (ST102).

When the vehicle 2 arrives at the destination as a sampling location, the sample collecting system 1 performs preliminary excavation by using the preliminary excavation apparatus 12 (ST103). Upon the completion of the preliminary excavation, the sample collecting system 1 starts main excavation (ST104). In the main excavation, the sample collecting system 1 performs sampling (sample collection) and analysis of a sample to be analyzed concurrently with soil excavation. When determining that a sample to be analyzed has been acquired (i.e., detecting the completion of introduction of a sample to be analyzed into the sample processing apparatus 22) (Yes in ST105), the sample collecting system 1 temporarily stops the operation of excavation by the main excavation apparatus 13 (ST106).

Then, in the sample collecting system 1, the sample processing apparatus 22 processes the acquired sample to be analyzed (i.e., separates an analyte component by heating the sample to be analyzed) (ST107). Subsequently, the sample collecting system 1 delivers gas containing the analyte component obtained in the sample processing apparatus 22 to the sample analyzing apparatus 23, which in turn analyzes the delivered gas (ST108).

Then, when determining that an analysis result provided by the sample analyzing apparatus 23 is normal (Yes in ST109), the sample collecting system 1 ends the sample collecting process. When the analysis resort is not normal (No in ST109), the sample collecting system 1 re-starts the operations for excavation and executes the same subsequent steps as described above. However, in some embodiments, when the analysis resort is not normal (No in ST109), the sample collecting system 1 may select one step from the steps ST101 to ST103; that is, acquiring sampling position information (step ST101), moving the vehicle (step ST102), and performing preliminary excavation (step ST103), and start to perform the selected step and the same subsequent steps as described above.

When a piece of the sampling position information includes a plurality of sampling positions, the sample collecting system 1 can collect samples at the plurality positions by repeatedly executing the operations of the same process steps as described above.

Specific embodiments of the present invention are described herein for illustrative purposes. However, the present invention is not limited to those specific embodiments, and various changes may be made for elements of the embodiments without departing from the scope of the present invention.

For example, the sample collecting method and the sample collecting system of the present invention may be used to collect samples of resources on an extraterrestrial body other than the Moon. In other cases, the sample collecting method and the sample collecting system of the present invention may be used on the earth. In some cases, the sample collecting method and the sample collecting system of the present invention may be configured such that two or more analyte components are analyzed at the same time by using the sample analyzing apparatus. In the embodiments of the sample collecting method and the sample collecting system as described above, not all elements therein are essential. Thus, various modifications including elimination of some elements may be made to the embodiments as appropriate without departing from the scope of the invention.

Glossary

-   1 sample collecting system -   2 vehicle -   10 travel device -   11 chassis -   12 preliminary excavation apparatus -   13 main excavation apparatus -   14 system main body -   15 crawler -   16 scoop -   17 arm -   18 boom -   19 support device -   20 baseplate -   22 sample processing apparatus -   23 sample analyzing apparatus -   24 apparatus movement mechanism -   26 power supply device -   27 main control device -   31 screw -   31A blade -   32 hollow rod -   32A opening -   33 motor -   35 motor -   35A shaft -   41 rotation shaft -   42 bearing -   43 bearing -   44 motor -   46 holder -   47 support frame -   51 core -   51A right surface -   52 outer cylinder -   55 recess -   57 heater -   58 measurement hole -   59 vent hole -   59A axial portion -   59B radial portion -   61 sample inlet -   63 gas delivery port -   64 sintered metal filter -   67 sample discharge port -   69 land surface -   70 preliminary borehole -   70A bottom surface -   70B sloped side surface -   71 surplus soil -   73 main borehole -   81 shutter -   91 vehicle control device -   92 excavation control device -   93 sample processing control device -   94 sample analyzing control device -   96 battery 

1. A sample collecting method comprising: forming a first borehole that reaches a first depth from a land surface by preliminary excavation of soil, the first depth being less than a predetermined sampling depth from the land surface; forming a second borehole that has a smaller opening than the first borehole and reaches a second depth from the land surface by further excavation of soil in the first borehole, the second depth being equal to or greater than the sampling depth; and while forming the second borehole, transferring part of soil present at the sampling depth in the second borehole to the land surface as a sample for analysis.
 2. The sample collecting method according to claim 1, wherein the step of forming the first borehole is performed by a preliminary excavation apparatus with a scoop or a blade.
 3. The sample collecting method according to claim 1, wherein the step of forming the second borehole is performed by a main excavation apparatus with a screw.
 4. The sample collecting method according to claim 3, wherein the step of forming the first borehole comprises forming a bottom surface and a sloped side surface connecting the bottom surface with the land surface, and wherein the step of forming the second borehole comprises moving the main excavation apparatus through the sloped side surface to the bottom surface.
 5. The sample collecting method according to claim 1, wherein the step of forming the first borehole is performed by blasting soil on the land surface.
 6. The sample collecting method according to claim 1, further comprising a sample supply step for supplying at least a portion of the sample for analysis that has been transferred to the land surface, to a sample analyzing apparatus installed on the land surface.
 7. The sample collecting method according to claim 6, further comprising a separation step for separating one or more analyte components from the sample for analysis by processing the sample for analysis that has been transferred to the land surface, wherein the sample supply step comprises supplying the one or more analyte components to the sample analyzing apparatus as part of the sample for analysis.
 8. The sample collecting method according to claim 7, wherein the separation step comprises separating water as an analyte component from the sample for analysis by heating the sample for analysis.
 9. A sample collecting system comprising: a preliminary excavation apparatus for forming a first borehole that reaches a first depth from a land surface by preliminary excavation of soil, the first depth being less than a predetermined sampling depth from the land surface; and a main excavation apparatus for forming a second borehole that has a smaller opening than the first borehole and reaches a second depth from the land surface by further excavation of soil in the first borehole, the second depth being equal to or greater than the sampling depth, wherein the main excavation apparatus comprises a screw for excavation, and wherein, by rotating the screw, part of soil present at the sampling depth in the second borehole is transferred to the land surface as a sample for analysis.
 10. The sample collecting system according to claim 9, wherein the preliminary excavation apparatus is provided with a scoop or a blade.
 11. The sample collecting system according to claim 9, further comprising a sample analyzing apparatus installed on the land surface and configured to analyze one or more analyte components included in the sample for analysis that has been transferred to the land surface.
 12. The sample collecting system according to claim 11, wherein the main excavation apparatus is movable between a standby position in which the main excavation apparatus lies horizontally along the land surface and an operating position in which the main excavation apparatus stands upright relative to the land surface, and wherein the sample analyzing apparatus is moved between the standby position and the operating position together with the main excavation apparatus.
 13. The sample collecting system according to claim 11, further comprising a sample processing apparatus configured to perform a heat treatment process for separating gas containing water, the water being an analyte component, from the sample for analysis.
 14. The sample collecting system according to claim 13, wherein the main excavation apparatus comprises a hollow rod configured to accommodate the screw, wherein the hollow rod defines an opening for discharging the sample for analysis that the screw has transferred to the land surface, and wherein the sample analyzing apparatus is installed at a location where the sample for analysis discharged from the opening falls by gravity.
 15. The sample collecting system according to claim 13, wherein the sample processing apparatus comprises: a core formed with a recess for accommodating the sample for analysis for the heat treatment process; and an outer cylinder arranged to surround the core, wherein the core is rotatably provided within the outer cylinder, wherein the outer cylinder defines a sample inlet that is a through hole into which the sample for analysis is provided, and wherein the sample inlet is formed such that the recess is brought into communication with an outside environment through the sample inlet only when the core is at a predetermined rotational position.
 16. The sample collecting system according to claim 11, further comprising a vehicle equipped with the preliminary excavation apparatus, the main excavation apparatus, and the sample analyzing apparatus. 